Code switching applied by air traffic controller in air navigation services

Air Traffic Controller is one of the occupations that mostly using language to interact on their service between them or to pilot and related units in air navigation service. To conduct ground to ground communication, a special language or radiotelephony, is deliberately created for air traffic controller and flight crew. In the ground to ground communication Air Traffic Controller using English for Specific Purposes (ESP) or aviation phraseology but in some case the Controller is applied to switch it into local language. The findings obtained regarding code switching in ground to ground communication amongst Air Traffic Service units occur when there is a message to be conveyed and purpose of the conversation not listed in the phraseology, that has been circulated in Document 9432 (Manual of Radiotelephony) published by International Civil Aviation Organization, where the message can be send clearly and precisely on target as desired by the messenger.